$J$ $K$ $L$ If: $ JK = 8x + 9$, $ KL = 7x + 2$, and $ JL = 71$, Find $KL$.
From the diagram, we can see that the total length of ${JL}$ is the sum of ${JK}$ and ${KL}$ $ {JK} + {KL} = {JL}$ Substitute in the expressions that were given for each length: $ {8x + 9} + {7x + 2} = {71}$ Combine like terms: $ 15x + 11 = {71}$ Subtract $11$ from both sides: $ 15x = 60$ Divide both sides by $15$ to find $x$ $ x = 4$ Substitute $4$ for $x$ in the expression that was given for $KL$ $ KL = 7({4}) + 2$ Simplify: $ {KL = 28 + 2}$ Simplify to find ${KL}$ : $ {KL = 30}$